Constant-gas-flow regulator



May 20 1924. 1,494,856

R. P. MASE CONSTA NT GAS FLOW REGULATOR Filed Sent. 1, 1922 [AWE/V7019. C2 922w. Z7 M M Patented May 29, 1924.

; mate ROSCOE P. MASE, OF WILKINSBUBG, PENNSYLVANIA..,

CONSTANT-GAS-FLOW ,REGULATOR.

Application filed September Gas-Flow Regulators, of which the following is a specification.

The object of this invention is to provide apparatus whereby the volumetric flow of gas through a conduit may be automatically maintained at a constant or substantially constant rate; The invention may be used wherever it is necessary or desirable to maintaina constant rate of flow of a gas, and is particularly applicable to chemical processes and continuous gasanalysis methods wherein such a'measured flow of gas is necessary.

Heretofore the usual practice in maintaining a constant rate of gas flow has been to provide a gas conduit "with a constricted portion dividing the conduit into high and low pressuresections, and'connect a U-tube to the conduit, one leg being attached at one side of the constriction and the other at the other side. A body of liquid is placed in the U-tube and a scale between the two columns of liquid in the legs of the tube indicates the difference-between the levels of the liquid and hence the difference be tween the pressures of gas at opposite sides of the constriction. Then the desired difference in pressure has been established it is" maintained by manual control of a valve arranged in the conduit. To be assured 'of a rate of flow which is constant within the permissible range of variation, it is neces sary to watch the Utube quite closely, principally because variations in. resistance to flow of gas cause quite large variations in the gas pressure relation between the two sides of the constriction.

duit through which gas flows is provided with a constricted portion which divides the conduit into high pressure inlet and low pressure outlet sections, and means are associated with the conduit sections for automatically maintaining a substantially constant differential between the pressures of gas flowing through the two conduit sections. The automatic 'controlmeans include a gas reliefvalve on the high pressure or inlet conduit section, and pressureopera'ted means communicating withthe low pressure 1, 1922. Serial No. 555,323. 7 w

or outlet conduit section for controlling the relief valve. f i

In the accompanying drawings'tliere are diagrammatically illustrated in Figs. 1, 2 and 3 tliree einbodiments of'the invention, the several views of the apparatus being vertical centralsections.

Having reference first to theembodiment of the invention illustrated in Fig. 1, a gas conduit is divided by means of an orificed diaphragm 1 into'a high-pressure inlets'ec tion 2 and a low pressureoutlet section}. Flow of gas into' the inlet section may be controlled by a valve l which may be-an ordinary manually operated valve; "or; if

desiredf an automatic P essure reducing. valve. In this, the preferred embodin'ient of the invention, the gas relief valve on the high pressure conduit section takes theform of a tubeextend ng from such conduit scction tothe bottom portion of a liquid col umn, the tube having an open end at the bottom of such column-so that gas may escape from the lower end of the tube under pressure depending upon the height of the column of liquid above the end of the tube.

The column .of liquid which controls thepressure of the gas in the high pressure conduit section is regulated in such manner that the height of the colum'n'vaiies in pro portion to the gas pressure changes in th low, pressure section of the'conduit;

Referring again to Fig. 1, a'suitable coir tainer, which may take the form'of a large bottle 5,is provided with agas tight stopper- 6 through which there extends a tubular casing 7. The horizontal crosss ection' of container 5 shouldbe quite-large'in relation to'casing 7. The lowerend of easing 7 ex tends nearly to the bottom of containeffi and its upper end is provided with an open ing 8 whereby the casing mayzbe' open' to the atmosphere or be placed incommu'mca- According to the present invention a con-i tion with a gas-receiving vessel. A tube 9'1 is attached" at its upper end to conduit seer forms a liquid coluinn exertingjits pressure in valv'e-likeform against the lower end of tube 9." A'tube 11 connects conduitsection with-the interior of-container' i5 above'the liquid therein so that the prfessur of gas in section 3 is transmitted'to the body of liquid 10' outside of casing Tand thereby controls theheight of the column of liquid within the casing.

In the operation of the apparatus there is first placed in the gas conduit a diaphragm 1 having an orifice or capillary of the size required to give the desired rate of flow with a given pressure differential. The particular liquid placed in container 5 is determined by the use to which the apparatus to be put, consideration being given both to the chemical properties of the liquid and to its specific gravity. Valve 8 is regulated so that when the gas is flowing normally through the conduit a small amount .of gas will escape from the bottom of tube 9 against the hydrostatic. pressure of the column of liquid within casing 7 This gas may escape either to the atmosphere or through opening 8 or to a suitable gas receiver attached to this opening.

When thepressure of gas in the low pressure conduit section 3 increases, the column of liquid within casing 7 proportionately rises and prevents the escape of gas through the lower end of tube 9 until the pressure of gas in conduit'section 2 has increased in proportion to that of the gas in sectionB. In asimilar manner when the pressure of the gas in conduit 8 diminishes, the height of the column of liquid in casing 7 is lowered thereby diminishing by an equal amount the pressure in section 2. In this way there is automatically maintained. a constant diflerence-between the pressures of gas in the two conduit sections on opposite sides of the constricted portion or diaphragm 1. It has been found that, within the range of accuracy required by the precision of gas flow measurements. the rate of flow of gas through the conduit may be maintained constant.

In the embodiment of the invention illustrated in Fig. 2 the liquid column valve of Fig. 1 is displaced by a float-controlled valve. WVithin casing 7 there is a float 12 which, through rod 13, a lever 14.- pivoted at 15 to a suitable support, and a link 16, controls a valve 17 attached to high pressure conduit section 2 Otherwise the apparatus of Fig. 2 is the same as that of Fig. 1.

In the operation of the apparatus of Fig. 2-, valve 17 is so set that a small amount of gas escapes through it when gas is flowing normally through the conduit. When the pressure of gas in conduit section 3 increases, the liquid in 7 rises, exerting pressure on float 12.1 This pressure is transmitted to valve 17 thereby increasing gas pressure in the high pressure side of conduit. When pressure in section 3 diminishes, valve 17 will similarly be under less pressure. Thus, irrespective of the changes of pressure usually experienced, the pressure diflerential is automatically maintained constant sothat the rate of flow is substantially the same.

In the embodiment of the invention illus-- trated in Fig. 3 the gas relief valve 17* is connected, through a rod 16*, a pivoted lever 14t and arod13 ,to a flexible diaphragm 18 which closes an opening in a casing 19 placed in communication with low pressure conduit section 3 by means of a tube 11*. The diavhragm may be held yieldingly towards casing 19 by means of a spring 20, the tension of which may be adjusted by a suitable screw 21. The operation of the apparatus of Fig. 8 will be readily understood from the explanation of the operation of the apparatus previously described.

It is characteristic of the several embodiments of the invention that the pressure of gas in the inlet or high pressure conduit section is automatically controlled in proportion to that of the gas in the outlet or low pressure conduit section, in the latter of which the pressure varies due to changes in resistance to flow incident to conditions of service. All forms of apparatus illus trated are also similar in that the constant pressure'difl'erential is maintained by a re lief valve on the high pressure conduit section controlled by the gas pressure in the low pressure conduit section. In the apparatus of Fig. 1 a hydrostatic valve is used, and mechanical valves in those of F igs.v 2 and 3. Manifestly the invention may, with in the scopeof the appended claims, be

practiced by other forms of apparatus than those specifically shown and described.

I claim:

1. In a constant gas flow apparatus, the combination with a conduit having a constricted portion dividing the conduit into high and low pressure sections, of a gas relief valve on the high pressure section, and pressure-operated means comn'iunicating with the low pressure section for controlling said valve whereby a constant difierential is automatically maintained between the pressures of gas flowing through said conduit sections.

2. In a constant gas flow apparatus, the combination with a conduit having a constricted portion dividing the conduit into high and low pressure sections, of a liquid column, a tube connected at one end to said 

